Abstract:

Disclosed herein is a device for controlling the temperature of batteries
for electric vehicles. The device includes a thermoelectric semiconductor
unit, a thermoelectric semiconductor unit, a temperature sensor, and a
battery controller. The thermoelectric semiconductor unit is configured
such that a portion thereof is exposed in a battery tray. The
thermoelectric semiconductor unit controller causes the thermoelectric
semiconductor unit to radiate heat, and causes the thermoelectric
semiconductor unit to absorb heat. The temperature sensor detects and
outputs the temperature of the battery tray. The battery controller
outputs the heat radiating control signal to the thermoelectric
semiconductor unit controller when the temperature detected by the
temperature sensor is lower than a predetermined value, and outputting
the heat absorbing control signal to the thermoelectric semiconductor
unit controller when the temperature detected by the temperature is equal
to or higher than the predetermined value.

Claims:

1. A device for controlling a temperature of batteries for electric
vehicles, comprising:a thermoelectric semiconductor unit configured such
that a portion thereof is exposed in a battery tray, thus radiating heat
into a battery tray when input current flows in a first direction and
absorbing heat inside the battery tray when the input current flows in a
second direction;a thermoelectric semiconductor unit controller for
causing the thermoelectric semiconductor unit to radiate heat by
supplying the current, which flows in the first direction, to the
thermoelectric semiconductor unit when a heat radiating control signal is
input thereto, and causing the thermoelectric semiconductor unit to
absorb heat by supplying the current, which flows in the second
direction, to the thermoelectric semiconductor unit when a heat absorbing
control signal is input thereto;a temperature sensor for detecting and
outputting a temperature of the battery tray; anda battery controller for
outputting the heat radiating control signal to the thermoelectric
semiconductor unit controller when a temperature detected by the
temperature sensor is lower than a predetermined value, and outputting
the heat absorbing control signal to the thermoelectric semiconductor
unit controller when the temperature detected by the temperature is equal
to or higher than the predetermined value.

2. The device according to claim 1, wherein the thermoelectric
semiconductor unit comprises:thermoelectric semiconductor elements, which
are connected to the thermoelectric semiconductor unit controller, and
are configured to radiate heat when the input current flows in the first
direction and to absorb heat when the input current flows in the second
direction; andheat radiating fins, which are configured such that first
ends thereof are exposed in the battery tray and such that second ends
are connected to the thermoelectric semiconductor elements, thus
transmitting the heat, radiated by the thermoelectric semiconductor
elements, to the battery tray, and absorbing the heat inside the battery
tray so as to be transmitted to the thermoelectric semiconductor
elements.

3. The device according to claim 1, further comprising a cooling fan that
is located in an intake port or an exhaust port of the battery tray to
radiate the heat inside the battery tray,wherein the battery controller
operates the cooling fan when a detection temperature of the temperature
sensor is equal to or higher than the predetermined value.

4. The device according to claim 3, wherein the thermoelectric
semiconductor unit is configured such that a portion thereof is located
so as to be exposed in the exhaust port of the battery tray.

5. The device according to claim 1, further comprising a heater that is
located in an intake port of the battery tray to supply heat to the
battery tray,wherein the battery controller operates the heater when a
detection temperature of the temperature sensor is lower than the
predetermined value.

6. The device according to claim 1, further comprising:an auxiliary
battery for supplying power to the thermoelectric semiconductor unit via
the battery controller; anda switch for controlling connection between
the auxiliary battery and the battery controller.

7. The device according to claim 1, further comprising:an inlet three-way
valve, which is located in an intake port of the battery tray, and is
configured to isolate air inside the battery tray from external air and
to recirculate the air inside the battery tray;an outlet three-way valve,
which is located in an exhaust port of the battery tray, and is
configured to isolate the air inside the battery tray from the external
air and to recirculate the air inside the battery tray; anda
recirculation air pipe, which is configured such that one end thereof is
connected to the inlet three-way valve and such that a remaining end
thereof is connected to the outlet three-way valve, thus enabling the
internal air to be recirculated by causing air, which is discharged from
the exhaust port, to be provided to the intake port.

8. The device according to claim 1, further comprising a heat insulating
material, which is mounted outside the battery tray to isolate air inside
the battery tray from air outside the battery tray.

Description:

TECHNICAL FIELD

[0001]The present invention relates to a device for controlling the
temperature of batteries for electric vehicles (including hybrid
vehicles).

[0002]More particularly, the present invention relates to a device for
controlling the temperature of batteries for electric vehicles, which can
cool batteries, which are mounted in an electric vehicle, using
thermoelectric semiconductor elements.

BACKGROUND ART

[0003]Generally, vehicles are classified into steam vehicles, internal
combustion engine vehicles, and electric vehicles according to the type
of power source. Of the vehicles, the electric vehicle is currently
attracting more attention as a means for solving the problem of serious
atmospheric pollution due to the exhaust gas of internal combustion
engine vehicles and the problem of increased fuel expenses due to the
high price of oil.

[0004]Such an electric vehicle is a device that uses electricity as its
power source, and is moved by operating an electric motor using
electrical energy, unlike a general vehicle, which moves using the energy
that is obtained by burning petroleum-based fuel in an internal
combustion engine.

[0005]Furthermore, the electric vehicle generates hardly any noise or
vibrations, and does not discharge any exhaust gas, so that it does not
cause any smell and does not pollute the atmosphere.

[0006]The electric vehicle is designed to be moved based on the principle
of driving wheels by rotating an electric motor using electrical energy.
Battery energy having a high-voltage characteristic is necessarily
required in order to move the vehicle.

[0007]However, currently, a high battery energy, which is sufficient to
operate an electric vehicle, cannot be realized using only a single
battery, and thus a plurality of batteries must be connected in series or
in parallel not only to realize a high voltage but also to maintain a
long lifespan.

[0008]An entity in which a plurality of batteries is aggregated and held
is called a battery pack. In practice, the battery pack is fastened to a
tray having a box shape, and is then mounted in an electric vehicle.

[0009]The performance and lifespan of the above-described batteries are
maintained by appropriately radiating the high heat that is generated
upon operation. For example, the batteries are cooled using air inside or
outside a vehicle. When air inside or outside a vehicle is used as
described above, a delay occurs until the temperature of the batteries
reaches a required appropriate temperature because air outside the
vehicle can be anywhere within wide temperature and humidity ranges.
Accordingly, a problem occurs in that the performance of the batteries is
lowered until the temperature of the batteries falls within a normal
temperature range.

[0010]FIG. 1 is a diagram showing the construction of a prior art battery
cooling device.

[0011]Referring to FIG. 1, the battery cooling device includes a plurality
of batteries 1, which are mounted in a battery tray 2 and are spaced
apart from each other at regular intervals, the battery tray 2, which is
configured such that the plurality of batteries 1 is mounted therein, and
a cooling fan 3, which is configured to discharge heat, which is radiated
from the batteries 1, at one side of the battery tray 2.

[0012]In the above-described battery cooling device, the cooling fan 3 is
mounted in the battery tray 2, in which the plurality of batteries 1 is
mounted, and an auxiliary battery 4 is connected to the cooling fan 3 via
a starting switch 5 and a battery controller 6.

[0013]Furthermore, a temperature sensor 7 is mounted in the battery tray
2. A relay is provided in the battery controller 6, and is configured to
be controlled in response to a detection signal from the temperature
sensor 7 and to interrupt the supply of power to the cooling fan 3 or
supply the power to the cooling fan 3.

[0014]The prior art cooling device, described above, causes the battery
controller 6 to maintain an appropriate temperature according to the
detection signal from the temperature sensor 7 when the starting switch 5
is merely turned on, and can control an increase in the temperature of
the batteries at room temperature to some extent. However, the prior art
cooling device cannot actively response to variations in the temperature
conditions outside a vehicle, that is, low or high temperature
conditions. This is a major cause of reduction in the performance of the
batteries.

[0015]In order to solve the above-described problems occurring in the
prior art, a method of supplying the exhaust gas of a vehicle, or cool
air, which is obtained through heat exchange in an air-conditioner, to
batteries is used. However, this method not only makes the device
complicated but also makes it difficult to control, and thus the
manufacturing cost of each vehicle is increased.

[0016]Furthermore, there is a method of thermally connecting a heat sink
and the electrodes of batteries to each other and heating or cooling the
heat sink. However, this method is problematic in that it is difficult to
select and use the medium that is used to heat or cool the heat sink and
in that a separate heat source must be provided.

[0017]Based on semiconductor cooling and heating elements, there is a
method of attaching thermoelectric cooling elements to the respective
outer surfaces of batteries and performing heating and cooling using
separate heat transfer media. In this case, there is a problem in that
the heat generated in high-capacity electric vehicle batteries cannot be
cooled to an appropriate temperature due to the amount of heat energy
that is transmitted to the batteries, depending on the transfer media,
and due to a transfer time delay. Furthermore, the main body casing of
each battery is generally made of thick plastic material, rather than
metal, so that individual batteries cannot be effectively cooled due to
the low thermal conductivity thereof, even if the main body casing is
cooled. In the thermoelectric semiconductor elements, the outer surface
thereof performs a heat radiating operation while a cooling surface is
formed therein to perform a cooling operation. In the case where the
operations are performed in reverse, reverse conditions are established.
In the prior art, there is no cooling device for protecting semiconductor
elements from the heat that is generated at the time of reversible
reaction of elements, so that a problem occurs in that the elements are
overheated and damaged upon practical application.

[0018]Unlike a general battery, such as a lead acid battery, an electric
vehicle high-voltage battery provides a high voltage using a combination
of a plurality of individual batteries. In the case where cooling is
achieved through rapid heat transfer in this process, and the batteries
are place at a low temperature, means for directly cooling and heating
the individual batteries is required in order for the batteries to
realize normal performance when rapidly heating. However, this problem
cannot be solved using a method of cooling and heating the outer surface
of a battery package.

DISCLOSURE

Technical Problem

[0019]Accordingly, the present invention has been made keeping in mind the
above problems occurring in the prior art, and an object of the present
invention is to provide a device for controlling the temperature of
batteries for electric vehicles using thermoelectric semiconductor
elements, which enables the temperature of batteries to be maintained at
an appropriate level using thermoelectric semiconductor elements.

Technical Solution

[0020]In order to solve the above-described problems, the present
invention provides a device for controlling the temperature of batteries
for electric vehicles, including: a thermoelectric semiconductor unit
configured such that a portion thereof is exposed in a battery tray, thus
radiating heat into a battery tray when input current flows in a first
direction and absorbing heat inside the battery tray when the input
current flows in a second direction; a thermoelectric semiconductor unit
controller for causing the thermoelectric semiconductor unit to radiate
heat by supplying the current, which flows in the first direction, to the
thermoelectric semiconductor unit when a heat radiating control signal is
input thereto, and causing the thermoelectric semiconductor unit to
absorb heat by supplying the current, which flows in the second
direction, to the thermoelectric semiconductor unit when a heat absorbing
control signal is input thereto; a temperature sensor for detecting and
outputting the temperature of the battery tray; and a battery controller
for outputting the heat radiating control signal to the thermoelectric
semiconductor unit controller when the temperature detected by the
temperature sensor is lower than a predetermined value, and outputting
the heat absorbing control signal to the thermoelectric semiconductor
unit controller when the temperature detected by the temperature is equal
to or higher than the predetermined value.

Advantageous Effects

[0021]The optimal temperature of the batteries is satisfied by
automatically control the ON/OFF operation of the thermoelectric
semiconductor elements and the direction of current according to
conditions of use of the batteries, so that the batteries can realize
their optimal performance.

[0022]Furthermore, according to the present invention, semiconductor
cooling elements are used as a heat source for cooling and heating, so
that noise and vibrations, which are generated by the prior art cooling
device using a vehicle air-conditioner or heater or using a fan, can be
reduced.

[0023]Furthermore, according to the present invention, the heat radiating
operation and the heat absorbing operation can be controlled using a
single thermoelectric semiconductor element, so that the temperature
control device can be easily implemented.

[0024]Furthermore, according to the present invention, the heat insulating
material, which surrounds the batteries, the inlet three-way valve, and
the outlet three-way valve isolate the battery unit from the external
air, so that the batteries can be protected from variation in the
external temperature even when a vehicle is not traveling.

[0025]Furthermore, according to the present invention, the temperature of
the battery unit can be more effectively, rapidly and accurately
controlled when the temperature of the external air, having a wide
temperature range and a large volume, is controlled according to the
cooling flow that is formed in order of the heat insulating material,
which surrounds the batteries, the inlet three-way valve, the outlet
three-way valve and the thermoelectric semiconductor unit.

DESCRIPTION OF DRAWINGS

[0026]FIG. 1 is a diagram showing the construction of a prior art battery
cooling device;

[0027]FIG. 2 is a diagram showing the construction of a device for
controlling the temperature of batteries for electric vehicles using
thermoelectric semiconductor elements according to an embodiment of the
present invention;

[0028]FIG. 3 is a diagram showing the construction of a device for
controlling the temperature of batteries for electric vehicles using
thermoelectric semiconductor elements according to another embodiment of
the present invention; and

[0029]FIG. 4 is a diagram showing the internal construction of the
thermoelectric semiconductor unit of FIGS. 2 and 3.

[0031]A device for controlling the temperature of batteries for electric
vehicles using thermoelectric semiconductor elements according to a
preferred embodiment of the present invention is described in detail with
reference to FIG. 2 below.

[0032]FIG. 2 is a diagram showing the construction of the device for
controlling the temperature of batteries for electric vehicles using
thermoelectric semiconductor elements according to an embodiment of the
present invention.

[0033]Referring to FIG. 2, the device for controlling the temperature of
batteries for electric vehicles using thermoelectric semiconductor
elements according to an embodiment of the present invention includes a
plurality of batteries 11, a battery tray 12, a cooling fan 13, an
auxiliary battery 14, a starting switch 15, a battery controller 16, a
temperature sensor 17, a relay 18, a thermoelectric semiconductor unit
19, and a thermoelectric semiconductor unit controller 20.

[0034]The battery tray 12 is formed to have a hollow shape and, for
example, is mounted on the bottom of an electric vehicle while containing
the plurality of batteries 11 therein. This battery tray 12 is not
limited thereto, and, for example, may be mounted in the front or rear
portion or a vehicle.

[0035]The cooling fan 13 is located in the exhaust port of the battery
tray 12, and discharges heat, which is radiated from the batteries 11, by
sucking and discharging air inside the battery tray 12.

[0036]The above-described cooling fan 13 is connected to the auxiliary
battery 14 so that the heat, which is radiated from the batteries 11, can
be discharged to the outside via the starting switch 15 and the battery
controller 16.

[0037]The auxiliary battery 14 is used to supply low power to parts other
than parts that are supplied with power from the batteries 11, and is
mounted outside the battery tray 12.

[0038]Furthermore, the battery controller 16 causes power to be supplied
to the cooling fan 13 or the thermoelectric semiconductor unit 19 by
operating the relay 18 according to the temperature in the battery tray
12.

[0039]The temperature sensor 17 is mounted in the battery tray 12, and
detects and outputs the temperature in the battery tray 12.

[0041]Furthermore, the battery controller 16 is configured to supply power
to the cooling fan 13 and the thermoelectric semiconductor unit 19, or to
interrupt the supply of the power thereto, by controlling the operation
of the relay 18 in response to the detection signal of the temperature
sensor 17.

[0042]Meanwhile, as shown in FIG. 4, the thermoelectric semiconductor unit
19 is located between the cooling fan 13 and the batteries 11, and is
provided with thermoelectric semiconductor elements 21 and heat radiating
fins 22.

[0043]Each of the thermoelectric semiconductor elements 21 has a structure
in which two metals having different properties from each other are
bonded to each other, and performs a heat radiating operation or a heat
absorbing operation according to the direction of current (which is
called the Peltier effect). The heat radiating or absorbing operation
causes heat to be transmitted to the battery tray 12 via the heat
radiating fins 22.

[0044]The heat radiating fins 22 function to transmit heat to the battery
tray 12 when the thermoelectric semiconductor elements 21 perform the
heat radiating operation or the heat absorbing operation, and are
configured such that the first ends thereof are attached to the
thermoelectric semiconductor elements 21 and such that the second ends
thereof are exposed into the exhaust port of the battery tray 11.

[0045]Furthermore, the thermoelectric semiconductor unit controller 20 is
located between the thermoelectric semiconductor elements 21 and the
battery controller 16, and supplies current to the themioelectric
semiconductor elements 21 under the control of the battery controller 16.

[0046]In this case, it is necessary for the thermoelectric semiconductor
unit controller 20 to control the direction of the current that is
transmitted to the thermoelectric semiconductor elements 21. The reason
for this is because the thermoelectric semiconductor elements 21 perform
the heat radiating or absorbing operation according to the direction of
the flowing current.

[0047]Meanwhile, the thermoelectric semiconductor unit controller 20 and
the thermoelectric semiconductor elements 21 are connected to each other
using control wires 23.

[0048]The above-described temperature control device according to the
present invention enables the battery controller 16 to maintain an
appropriate temperature in response to the detection signal from the
temperature sensor 17 when the starting switch 15 is merely turned on.

[0049]That is, the battery controller 16 receives the detected temperature
from the temperature sensor 17, which is located in the battery tray 12.

[0050]Furthermore, if it is determined that the temperature received from
the temperature sensor 17 is equal to or greater than a predetermined
temperature, the battery controller 16 causes heat to be radiated by
sequentially operating the relay 18 and the cooling fan 13.

[0051]The battery controller 16 transmits a control signal to the
thermoelectric semiconductor unit controller 20, thus causing the heat
absorbing operation to be performed by causing the thermoelectric
semiconductor unit controller 20 to supply current to the thermoelectric
semiconductor elements 21. Subsequently, the heat radiating fins 22
transfer the heat in the battery tray 11 to the thermoelectric
semiconductor elements 21 thanks to the heat absorbing operation of the
thermoelectric semiconductor elements 21, thus reducing the temperature
of the battery tray 11.

[0052]Meanwhile, if it is determined that the temperature received from
the temperature sensor 17 is lower than the predetermined temperature,
the battery controller 16 transmits a control signal to the
thermoelectric semiconductor unit controller 20, thus causing the heat
radiating operation to be performed by causing the thermoelectric
semiconductor unit controller 200 to supply current to the thermoelectric
semiconductor elements 21. Subsequently, the heat radiating fins 22
transmit the heat of the thermoelectric semiconductor elements 21 to the
battery tray 11 thanks to the heat radiating operation of the
thermoelectric semiconductor elements 11, thus increasing the temperature
in the battery tray 11.

[0053]Meanwhile, a combination of the thermoelectric semiconductor
elements and the cooling fan has been described herein, but a combination
of the thermoelectric semiconductor elements and a heater may be made.

Mode for Invention

[0054]Meanwhile, a device for controlling the temperature of batteries for
electric vehicles using thermoelectric semiconductor elements according
to another embodiment of the present invention is described in detail
with reference to FIG. 3 below.

[0055]FIG. 3 is a diagram showing the construction of the device for
controlling the temperature of batteries for electric vehicles using
thermoelectric semiconductor elements according to another embodiment of
the present invention.

[0056]Referring to FIG. 3, the device for controlling the temperature of
batteries for electric vehicles using thermoelectric semiconductor
elements according to the embodiment of the present invention includes a
plurality of batteries 11, a battery tray 12, a cooling fan 13, an
auxiliary battery 14, a starting switch 15, a battery controller 16, a
temperature sensor 17, a relay 18, a thermoelectric semiconductor unit
19, a thermoelectric semiconductor unit controller 20, an inlet three-way
valve 30, an outlet three-way valve 31, a heat insulating material 32,
and a recirculation air pipe 33.

[0057]The battery tray 12 is formed to have a hollow shape and, for
example, is mounted on the bottom of an electric vehicle and contains the
plurality of batteries 11 therein. The battery tray 12 is not limited
thereto, and, for example, may be mounted in the front or rear portion or
a vehicle.

[0058]The cooling fan 13 is located in the intake or exhaust port of the
battery tray 12, and discharges heat, which is radiated from the
batteries 11, by sucking and discharging the air inside the battery tray
12, or forcibly blowing air outside the vehicle into the battery tray 12.

[0059]The above-described cooling fan 13 is connected to the auxiliary
battery 14 so that the heat radiated from the batteries 11 can be
discharged to the outside via the starting switch 15 and the battery
controller 16.

[0060]Furthermore, the inlet three-way valve 30 is used to change the
direction of inlet air or to isolate the air inside the battery tray 12
and the air outside the battery tray 12 from each other, and is located
in the intake port of the battery tray 12.

[0061]Furthermore, the outlet three-way valve 31 is used to change the
direction of outlet air or to isolate the air inside the battery tray 12
and the air outside the battery tray 12 from each other, and is located
in the exhaust port of the battery tray 12.

[0062]Furthermore, the heat insulating material 32 is located outside the
battery tray 12, so that the outer portion of the battery tray 12 can be
thermally insulated.

[0063]The recirculation air pipe 33 is used as a circulation path for
recirculating air inside the battery tray 12, and is configured such that
the inlet port thereof is connected to the inlet three-way valve 30 and
such that the outlet port thereof is connected to the outlet three-way
valve 31.

[0064]The inlet three-way valve 30 and the outlet three-way valve 31,
described above, isolate the air inside the battery tray 12 and the air
outside the battery tray 12 from each other in the state in which a
vehicle system is not operated, by which the batteries 11 are little
affected by the external temperature when a vehicle is exposed to low
temperatures or high temperatures.

[0065]Furthermore, the recirculation air pipe 33 enables the heat, which
is generated due to the use of the batteries 11 while the vehicle is
traveling, to be recirculated in the battery tray 12 via the outlet
three-way valve 31-recirculation air pipe 33-inlet three-way valve
31-batteries 11-cooling fan 13-thermoelectric semiconductor unit 19 of
the battery tray 12. Accordingly, the heat inside a battery unit, which
is generated while the vehicle is traveling, is cooled by the
thermoelectric semiconductor unit and is rapidly supplied again, and thus
air recirculation can be achieved such that the batteries can be used in
a normal temperature range.

[0066]In this case, it is determined by the battery controller 16 whether
it is necessary to suck the external air or to discharge the internal air
through the switching operation of the inlet three-way valves 30 or the
outlet three-way valve 31.

[0067]The auxiliary battery 14 is used to supply low power to parts other
than parts that are supplied with power from the batteries 11, and is
mounted outside the battery tray 12.

[0068]Furthermore, the battery controller 16 causes power to be supplied
to the cooling fan 13 or the thermoelectric semiconductor unit 19 by
operating the relay 18 according to the temperature in the battery tray
12.

[0069]The temperature sensor 17 is mounted in the battery tray 12, and
detects and outputs the temperature in the battery tray 12.

[0071]Furthermore, the battery controller 16 is configured to supply power
to the cooling fan 13 and the thermoelectric semiconductor unit 19, or to
interrupt the supply of the power thereto, by controlling the operation
of the relay 18 in response to the detection signal of the temperature
sensor 17.

[0072]Meanwhile, as shown in FIG. 4, the thermoelectric semiconductor unit
19 is located between the cooling fan 13 and the batteries 11, and is
provided with thermoelectric semiconductor elements 21 and heat radiating
fins 22.

[0073]Each of the thermoelectric semiconductor elements 21 has a structure
in which two metals having different properties from each other are
bonded to each other, and performs a heat radiating operation or a heat
absorbing operation according to the direction of current (which is
called the Peltier effect). The heat radiating or absorbing operation
causes heat to be transmitted to the battery tray 12 via the heat
radiating fins 22.

[0074]The heat radiating fins 22 function to transmit heat to the battery
tray 12 when the thermoelectric semiconductor elements 21 perform the
heat radiating operation or the heat absorbing operation, and are
configured such that the first ends thereof are attached to the
thermoelectric semiconductor elements 21 and such that the second ends
thereof are exposed in the exhaust port of the battery tray 11.

[0075]Furthermore, the thermoelectric semiconductor unit controller 20 is
located between the thermoelectric semiconductor elements 21 and the
battery controller 16, and supplies current to the thermoelectric
semiconductor elements 21 under the control of the battery controller 16.

[0076]In this case, it is necessary for the thermoelectric semiconductor
unit controller 20 to control the direction of the current that is
transmitted to the thermoelectric semiconductor elements 21. The reason
for this is because the thermoelectric semiconductor elements 21 perform
the heat radiating or absorbing operation according to the direction of
the flowing current.

[0077]Meanwhile, the thermoelectric semiconductor unit controller 20 and
the thermoelectric semiconductor elements 21 are connected to each other
using control wires 23.

[0078]The above-described temperature control device according to the
present invention enables the battery controller 16 to maintain an
appropriate temperature in response to the detection signal from the
temperature sensor 17 when the starting switch 15 is merely turned on.

[0079]That is, the battery controller 16 receives the detected temperature
from the temperature sensor 17, which is located in the battery tray 12.

[0080]Furthermore, if it is determined that the temperature received from
the temperature sensor 17 is equal to or higher than a predetermined
temperature, the battery controller 16 causes heat to be radiated by
sequentially operating the relay 18 and the cooling fan 13.

[0081]The battery controller 16 transmits a control signal to the
thermoelectric semiconductor unit controller 20, thus causing the heat
absorbing operation to be performed by causing the thermoelectric
semiconductor unit controller 20 to supply current to the thermoelectric
semiconductor elements 21. Subsequently, the heat radiating fins 22
transfer heat in the battery tray 11 to the thermoelectric semiconductor
elements 21 thanks to the heat absorbing operation of the thermoelectric
semiconductor elements 21, thus reducing the temperature of the battery
tray 11.

[0082]Meanwhile, if it is determined that the temperature received from
the temperature sensor 17 is lower than the predetermined temperature,
the battery controller 16 transmits a control signal to the
thermoelectric semiconductor unit controller 20, thus causing the heat
radiating operation to be performed by causing the thermoelectric
semiconductor unit controller 200 to supply current to the thermoelectric
semiconductor elements 21. Subsequently, the heat radiating fins 22
transmit the heat of thermoelectric semiconductor elements 21 to the
battery tray 11 thanks to the heat radiating operation of the
thermoelectric semiconductor elements 11, thus increasing the temperature
of the battery tray 11.

[0083]Meanwhile, a combination of the thermoelectric semiconductor
elements and the cooling fan has been described herein, but a combination
of the thermoelectric semiconductor elements and a heater may be made.